Patent application title: Device for Redirecting the Luminous Flux Emitted by One or More LED

Abstract:

The invention relates to a device for redistributing with axis rotated to
90° of the luminous flow emitted by one or more LEDs as secondary
optical component for the construction of sources, lamps, illuminating
bodies, and solid state optical signalling apparatuses. In one of its
basic forms the invention comprises a main optical element (1) and an
optical protection case (20) coupled by a pin (5) obtained in the element
(1) and a cavity (21) obtained in the case (20).

Claims:

1. A device for redistributing the luminous flow emitted by one or more
LEDs (34) as indicated in FIG. 1 and characterised in that it comprises a
main combined reflection/refraction optical element (1) made of PC and
provided with:a profile indicated by (2) that inferiorly by revolution
around the axis of symmetry defines a surface characterising a conical
cavity with the vertex positioned in opposite direction relative to the
primary lenses of the LEDs (34),a profile indicated by (4) that
superiorly by revolution around the axis of symmetry defines a surface
characterising a cupola-shaped cavity with the vertex positioned in the
direction of the primary lenses of the LEDs (34);a profile indicated by
(3) that laterally by revolution around the axis of symmetry defines a
surface characterising a cone frustum shaped solid with the vertex
positioned in the direction of the primary lenses of the LEDs (34),for
the purposes of the 90.degree. rotation of the optical axis of the
photometric solid emitted as well as to the variation of the upper and
lower angles referred to said axis relative to that of the LEDs (34).

2. The device as claimed in claim 1, characterised in that said device is
provided with a pin (5) for coupling to other components.

3. The device as claimed in claim 2, characterised in that said device is
coupled on an optical protection case (20) by means of an inner cavity
(21) for housing the pin (5) obtained in an inner thickening (23).

4. The device as claimed in claim 3, characterised in that said device is
provided with an optical protection case (20) whose upper thickened
region (23) determines a convex surface (22) so constructed as to have
optical characteristics of diffuse reflection which concurs in the
definition of the photometric solid.

5. The device as claimed in claim 4, characterised in that said device is
provided with an optical protection case (20) provided with a cavity (24)
for connection to a commercial solid state source.

6. The device as claimed in claim 5, as indicated in FIG. 2, characterised
in that interposed between the surface (22) on the thickened region (23)
and the main optical element (1) is an additional optical element (40)
made of plastic material with added metal-coating having specular
reflecting surface (41) which concurs in the definition of the
photometric solid.

7. The device as claimed in claim 6, characterised in that the optical
element (40) is provided with diffuse reflecting surface (41) which
concurs in the definition of the photometric solid.

8. The device as claimed in claim 6, characterised in that the main
optical element (1) and the additional element (40) are distanced by a
spacer element (50).

9. The device as claimed in claim 7, characterised in that the main
optical element (1) and the additional element (40) are distanced by a
spacer element (50).

10. The device as claimed in claim 6, as indicated in FIG. 3 characterised
in that the main optical element (1) has in the central part a hole (6)
instead of the pin (5) in order to allow the insertion of a separate pin
(60) provided with a retaining head (61) to reduce the slight luminous
flow dispersed along the direction of the optical axis of the LEDs (34).

11. The device as claimed in claim 7, as indicated in FIG. 3 characterised
in that the main optical element (1) has in the central part a hole (6)
instead of the pin (5) in order to allow the insertion of a separate pin
(60) provided with a retaining head (61) to reduce the slight luminous
flow dispersed along the direction of the optical axis of the LEDs (34).

12. The device as claimed in claim 8, as indicated in FIG. 3 characterised
in that the main optical element (1) has in the central part a hole (6)
instead of the pin (5) in order to allow the insertion of a separate pin
(60) provided with a retaining head (61) to reduce the slight luminous
flow dispersed along the direction of the optical axis of the LEDs (34).

13. The device as claimed in claim 9, as indicated in FIG. 3,
characterised in that the main optical element (1) has in the central
part a hole (6) instead of the pin (5) in order to allow the insertion of
a separate pin (60) provided with a retaining head (61) to reduce the
slight luminous flow dispersed along the direction of the optical axis of
the LEDs (34).

14. The device as claimed in claim 10, characterised in that the separate
pin (60) is made of metallic material.

15. The device as claimed in claim 14, characterised in that the separate
pin (60) is superficially coated with polished nickel.

16. The device as claimed in claim 14, characterised in that the separate
pin (60) is superficially coated with polished chrome.

17. The device as claimed in claim 11, characterised in that the separate
pin (60) is made of metallic material.

18. The device as claimed in claim 17, characterised in that the separate
pin (60) is superficially coated with polished nickel.

19. The device as claimed in claim 17, characterised in that the separate
pin (60) is superficially coated with polished chrome.

20. The device as claimed in claim 12, characterised in that the separate
pin (60) is made of metallic material.

21. The device as claimed in claim 20, characterised in that the separate
pin (60) is superficially coated with polished nickel.

22. The device as claimed in claim 20, characterised in that the separate
pin (60) is superficially coated with polished chrome.

23. The device as claimed in claim 13, characterised in that the separate
pin (60) is made of metallic material.

24. The device as claimed in claim 23, characterised in that the separate
pin (60) is superficially coated with polished nickel.

25. The device as claimed in claim 23, characterised in that the separate
pin (60) is superficially coated with polished chrome.

26. The device as claimed in claim 1, characterised in that the material
whereof the main optical element (1) is made is PMMA.

27. The device as claimed in claim 1, characterised in that the material
whereof the main optical element (1) is made is glass.

28. The device as claimed in claim 1, characterised in that the material
whereof the main optical element (1) is made is crystal.

29. The device as claimed in claim 1, characterised in that the material
whereof the optical protection case (20) is made is PMMA.

30. The device as claimed in claim 1, characterised in that the material
whereof the optical protection case (20) is made is glass.

31. The device as claimed in claim 1, characterised in that the material
whereof the optical protection case (20) is made is crystal.

32. The device as claimed in claim 1, characterised in that the material
whereof the additional optical element (40) is made is metal.

33. The device as claimed in claim 1, characterised in that the spacer
element (50) is obtained as an appendage of the additional optical
element (40).

34. The device as claimed in claim 1, characterised in that the spacer
element (50) is obtained as an appendage of the main optical element (1).

35. The device as claimed in claim 1, as described and illustrated herein
with reference to the figures of the accompanying drawings and for the
aforementioned purposes.

36. The device according to claim 1 and as described and illustrated
herein with reference to the figures of the accompanying drawings and for
the aforementioned purposes.

Description:

[0001]The present invention relates to a device for redirecting the
luminous flow emitted by one or more LEDs as a secondary optical
component for the construction of sources, lamps, illuminating bodies and
solid state optical signalling apparatuses.

[0002]The object of the present invention is to obtain with the lowest
possible fabrication costs with respect to what is known in the prior art
and available commercially a device for redistributing the luminous flow
emitted by one or more LEDs in such a way that the optical axis is
rotated by 90 and at the same time the emission angles can be varied
relative to said axis.

[0003]In the most general form, all current devices for redistributing the
luminous flow with rotation of the optical axis to 90° for LED
emitters provide for the use of conical solid structures with vertex
reversed and oriented towards the upper part of the primary lenses
integral with the LED emitters.

[0004]An additional characterisation of the devices currently in use is
that their conical shape is typically supported by a hollow cylindrical
structure within which are located the LEDs and which is fastened to the
outer edge of said emitter or to the surface/structure whereon they are
positioned.

[0005]Further variants of the devices currently in use provide for the use
or the modification of primary lenses so that at the top of the standard
convex shape of the surface of said lenses is obtained a depression with
conical shape with vertex towards the junction to semiconductor emitter
of the luminous flow.

[0006]The main object of the present invention is to provide superior
functional performance with respect to the prior art in relation to the
capability of also defining differently the angles of emission above and
below the optical axis rotated by 90° with respect to that of the
LED emitters and at the same time of obtaining a greater intensity of
emission due to the mutually combined functionalities of optical
reflection and refraction.

[0007]A further advantage of the invention, since it has no direct
connection to the LEDs is that it can be inserted within optical
protection cases typically in use in lamps and thereby to allow their
easy replacement if required for maintenance reasons or because of
changed requirements of the redistribution of the luminous flow by virtue
of the connection by conical insertion or in snap-in fashion.

[0008]These objects and advantages are all achieved by the invention in
question as it is characterised by the appended claims.

[0009]Additional characteristics and advantages of the present invention
will become more readily apparent from the following detailed description
of preferred, but not exclusive, embodiments of the invention, all based
on the same principle and illustrated purely by way of non limiting
example in the accompanying figures, in which:

[0010]FIG. 1 shows the section view of the invention comprising the set of
its elements among which the optical protection case (where for the sake
of illustration clarity the usual dashed lines are omitted) coupled onto
a characteristic solid state source shown in a lateral view;

[0011]FIG. 2 shows a variant of the invention shown in the same way as
FIG. 1 and characterised by an additional reflecting/diffusing element
and by an additional spacer element;

[0012]FIG. 3 shows an additional variant of the invention shown in the
same way as FIG. 2 and characterised by an additional element for
connecting to the optical protection case;

[0013]FIG. 4 shows the invention of FIG. 1 in which with dashed lines are
shown the modifications made to the distribution of the main luminous
flow produced by the LED emitters.

[0015]With reference to FIG. 1, the conformation of the main optical
element 1, preferably but not exclusively made of optical grade
polycarbonate, for the purposes of redistributing the luminous flow
according to what is described above and shown in FIG. 4 with the
reference number 100 is achieved by: [0016]a profile indicated by the
number 2 that inferiorly by revolution around the axis of symmetry
defines a surface characterising a conical cavity with the vertex
positioned in opposite direction relative to the primary lenses of the
LEDs indicated by the number 34 (unlike what is found in products
currently available on the market and according to the prior art),
[0017]a profile indicated by the number 4 that superiorly by revolution
around the axis of symmetry defines a surface characterising a
cupola-shaped cavity with the vertex positioned in the direction of the
primary lenses of the LEDs indicated with the number 34; [0018]a profile
indicated by the number 3 that laterally by revolution around the axis of
symmetry defines a surface characterising a cone frustum shaped solid
with the vertex positioned in the direction of the primary lenses of the
LEDs indicated by the number 34.

[0019]With reference to FIG. 1, the number 5 indicates a cylindrical pin
preferably with slight conicity obtained as an appendage of the element
1.

[0020]With reference to FIG. 1, the number 21 indicates a cylindrical
cavity, preferably with slight conicity located inside the thickened
region 23 of the optical protection case 20 to house the pin 5 and
achieve the mechanical coupling between the elements 20 and 1.

[0021]In relation to the optical protection case 20 of FIG. 1, preferably
but not exclusively made of optical grade polycarbonate, the thickened
region at the top 23 has an inner surface 22 that is convex towards the
inner cavity 24. Said convex surface 22 is preferably made in such a way
as to obtained a diffuse reflection.

[0022]With reference to FIG. 1, the number 33 indicates the edge for
fastening, in snap-in fashion or by screw or with other means, the
commercial solid state source 30 with the elements 20 and 1 previously
coupled to each other by insertion in the hollow region 24.

[0023]Also with reference to FIG. 1, the commercial solid state source 30
may also be of the type lacking the adapter ring 32 and constituted by
the sole electrical attachment 31 comprehensive of the
electrical/electronic circuits for controlling the current to the LED
emitters 34. This possibility, not shown in the figures, entails that the
edge of the electrical attachment serves the same function as the edge 33
of the adapter ring 32 for the purposes of fastening, in snap-in or
screw-in fashion, or by other means, to the optical elements 20 and 1.

[0024]With reference to FIG. 2, as an embodiment variant of the invention
indicated in FIG. 1, the reference 40 indicates a reflector/diffuser
element having a convex surface 41 of the specular reflecting or diffuse
reflecting type.

[0025]The element 40, made of metallic or plastic material with added
metal-coating, will be positioned by the element 1 at a distance
predetermined by means of a spacer element 50.

[0026]In some additional embodiment, not shown, the spacer element 50 may
be obtained as an appendage of the reflector/diffuser element 40 or
alternatively to the main optical element 1.

[0027]With reference to FIG. 2, the remaining elements shown serve the
same purpose indicated for the those of FIG. 1, whereto the reader is
referred for their description.

[0028]With reference to FIG. 3, as an additional embodiment of the
invention of FIG. 2, the number 6 indicates a hole at the centre of the
main optical element 1 instead of the cylindrical pin 5 into which is
inserted, during the coupling with the optical protection case 20, a
preferably metallic pin 60, with its surface preferably nickel- or
chrome-plated, provided with retaining head 61 to reduce the slight
luminous flow dispersed in the direction of the optical axis of the LEDs
34.

[0029]With reference to FIG. 3, the remaining elements shown serve the
same function indicated for those of FIG. 2, whereto the reader is
referred for their description.

[0030]It is specified that in accordance with the teachings provided by
the present description, the definition of the surfaces of the optical
elements will be subject to numerous dimensional variations in the
geometry of the profiles indicated with the numbers 4, 3, 2, 22, 41 for
the purposes of modifying the upper and lower angles of redistribution of
the luminous flow with axis of 90° relative to that of the LEDs
34, in order to meet the different application requirements.

[0031]Moreover, it is stressed that the invention and its described
variants may be subject to numerous changes of a practical-application
nature of the constructive details (among them, materials used and
systems for interconnecting the elements) without thereby departing from
the scope of the inventive idea as claimed below.